To comply with the Stage 2 Disinfection Byproduct Rule, the rolling quarterly average at each sample site must be below .080 mg/L (80 ug/L).
TTHM Chlorine Maintenance Special Samples
The North Texas Municipal Water District conducts chlorine maintenance throughout the water delivery system in February/March each year. Starting in 2018, the City of Plano began collecting samples to analyze disinfection byproducts during this time period. Samples are collected from the same 12 sites normally sampled plus the four pump stations. In 2019, Plano started conducting special sampling twice during the maintenance period. In 2020, samples were collected from the inlet and outlet locations at all four pump stations to monitor changes inside tanks. There was an error with the first set of samples collected at the Out location of Custer Pump Station and the In location of Stadium Pump Station. The chart below shows the received TTHM special sample results by location from both sample dates.